1. Patterns, Order & Organisation 2. Time For Some Changes 3. Chemical Reactions 4. Fast & Slow Reactions 5. Rusting out 6. Burning Is A Chemical Reaction 7. A New Breed Of Materials
* INVESTIGATE – Research the fuels used in rockets and explain their reactions, usefulness and dangers. Present your findings to the class
6
8.7 A New Breed of Materials
8.14 Putting fibres to the test page 266
Understanding & Inquiring page 268 Q’s 1 – 12
Understanding & Inquiring page 268 Q’s 13 - 21
* IMAGINE – page 268 do Question 22 (check out Jacplus Searchlight ID:eles-0859) * RECYCLING – page 272 do Question 13
7
Revision & Test
AssessOn Ch 8 Progress and Topic Test and written test.
Class notes
type of physical properties
maleability
ductility
elasticity
opacity - transparent, opaque, translucent, reflective
colour
shiny or dull
size
shape
texture
hard or soft
squishy
solid liquid or gas
Candle observations
1.
Rates of reaction
Expt 8.7 Aim: To observe the effect of temperature on a reaction Method
1. observe the reaction between HCl and Marble chip . Record your observation in the results table
2.gently heat the testtube containing acid and marble chip. observe and record results
Results
Observation table
Step 1
Acid and marble chip at room temp
I observed
on a scale of 1 to 5 this reaction was a
Step 2
Acid and marble chip at a higher temp
I observed
on scale of 1 to 5 this reaction was a
Discussion
Complete the questions
1. what indicated that a reaction was occurring?
2. how did this indication change when you heated the solution?
3. how does heat affect the rate of the reaction
Conclusion:
Effect of temperature.
Increasing the temperature increases the rate of reaction because the particles involved in the reaction are moving faster and bump into each other more often. This speeds up the reaction
Effect of concentration
Increasing the concentration increases the amount of particles in the slution available to take part in the reaction . so the reaction rate increases
Effect of surface area
By increasing the surface area - having a powder instead of a lump this increases the amount of places the reaction can take place. This increases the reaction rate.
complete question 1 to 9 p273
Rusting
Rusting is a form of combustion. This is where oxygen and water combine with iron. This is a slow reaction that may take 100 years to complete.
Rust Investigation 8.9
Set up the equipment and draw a clear well labelled diagram to describe the apparatus used in this investigation.
Diagram
See board Results
After 4 days the rusting looked like this
Diagram
After 6 days (wednesday lesson) the rusting looked like this and the water level was here.
(leave some space to do this diagram)
Conclusion
(leave 4 lines for some writing and a chemical equation)
Oxygen gas in the air inside the beaker has been converted to rust and has moved out of the air in the beaker. This means the water level inside the beaker has risen ( because oxygen has been taken out).
Combustion Reactions
Combustion reactions Are reactions where things are burnt in oxygen. We give them a special name - oxidation reactions. When an element combines with oxygen we say it has been oxidised. This can happen quickly or slowly.
An example of a slow oxidation reaction is rusting - here oxygen combines with iron to form iron oxide.
An example of a fast oxidation reaction is burning gas to heat water on the stove. Here we are burning propane to form carbon dioxide and water.
A general equation for this reaction is
(fossil fuel containing carbon) Fuel + oxygen ---> carbon dioxide and water
What is a fossil fuel? List three examples of fossil fuels- Remains of past living organism - eg coal , gas , oil
List and describe three examples of useful oxidation reactions. - fuel, , heating, decomposition of food,
Write a word equation for each of the three examples listed in question petrol + oxygen ----> water + carbon dioxide + heat
Fruit + oxygen -----> water and Carbon dioxide
wood + oxygen ----> water + carbon dioxide
Questions 1 to 8 p 276
A new breed of materials
Plastics are synthetic ie they are manufactured and do not occur naturally. Plastics have only been around for 100 years. They are the product of combining C, H, O as molecules in a repeating pattern
Fibres Natural fibres are found in nature. Egs. linen from flax plants, cotton, wool, silk from silk worms. We often spin these fibres to produce a regular thickness as a thread that can then be woven.
Synthetic fibres are useful because they long lasting, easy care, light, hold their colour. Egs include polyester, nylon, spandex. These fabrics are made by heating the plastic and pushing it through a spinneret to make a thread. it is then woven to make the fabric.
Blended fabrics are made of a combination of natural fibres and synthetic fibres to make a fabric with the properties we want. an eg is spandex combined with cotton and polyester to make leggings/skins.
Soaps and detergents these are chemical that are used for cleaning - they dissolve grease They have the physical properties of feeling slippery, solids or liquids , can be colourful They have the chemical properties of ; dissolve grease, biodegradable,
Physical properties - we use our senses to detect these (hard, soft, smell, colour, slippery etc) Chemical properties - the thing the chemical can do- the way it reacts with other chemicals- ( acids are sour and corrosive) (Metals react with acids to produce hydrogen gas)
PLastics as packaging
Is the packaging recyclable? - can be remelted and turned into another product eg cup
Is the packaging biodegradable? - it is broken down by nature - sunlight, oxygen, weak acidic water
Designing an experiment to investigate corrosion in different metals and under different conditions
1. the variables are - air, water, salt water, acid,
2. the control is oil
If a metal corrodes I would expect to see_colour change, going dull no longer shiny _ I would see a difference if I compared this metal to a piece of the same metal that is not exposed to the variable ; air, water, sea water, ___
Draw a diagram of the set up - label all the parts
How will you record your observations?
Solutions
air
air
water
water
salt water
salt water
acid
acid
oil
oil
Metal
today..DAY 0..
next weekDAY 8
today..DAY 0..
next weekDAY 8
today..DAY 0..
next weekDAY 8
today..DAY 0..
next weekDAY 8
today..DAY 0..
next weekDAY 8
copper
y - not as shiny
nc
y cloudy
dissolved
nc
zinc
y - parts were not as shiny
y, cloudy
y white
y
nc
iron
y - rusted
y, rusty
y cloudy/rusty
y
nc
Magnesium
nc
y - not as shiny gets dull
y cloudy and broken
y broken and sediment
bubbles
y
nc
Design an experiment to identify which substance gives out the most heat when it is burnt.
the variables are:
the things we will make sure are the same between all the substances we test are
are
the control is
The equipment will be set up like this (diagram 5 lines high)
To measure the heat given off we will .....measure the increase in temperature of 5 mLs of water
Results Table
Fuel
mass of fuel
mass of fuel after burning
mass of fuel that was burnt
starting temp of the 5mLs of water
temp of water after the fuel has gone out
Total increase of temperature
paper
tissue
stick
substance x
1.2g
0.5g
0.7g
18 C
28 c
10 C
substance y
3.4g
3.1g
0.3
20 C
23 C
3 C
hmwk ques 1 and 2 p 278
Final results
Fuel
temp increase per gram
paper
tissue
stick
substance X
14.4 / g
Substance Y
10 C/g
3 / 0.3 = 10 C/g
Find three more fuels that you predict are the best fuels -that is highest temperature per gram
What do they use as fuel in africa or qatar
Year 8 CHEMICAL CHANGE – Chapter 8
2. Time For Some Changes
3. Chemical Reactions
4. Fast & Slow Reactions
5. Rusting out
6. Burning Is A Chemical Reaction
7. A New Breed Of Materials
TEXTBOOK
Understanding
Established Extending
8.2 Time for Some Changes
AssessOn Ch 8 Pretest
8.1 Checking Out Properties (not Discuss & Explain) page 251
8.2 A Burning Candle page 252
http://www.dailymotion.com/video/x3jyupa
page 251 Q’s 1, 3, 4, 5
page 253 Q’s 1 – 8
page 253 Q 9
8.4 Heating copper carbonate page 255
8.5 Sodium sulfate & barium chloride page 255
8.6 Steel wool in copper sulfate page 255
page 256 Q’s 1, 2
8.8 Changing the rate of reaction page 259
(Check out Jacplus Searchlight ID: int-0230)
page 259 Q’s 1 - 6
eBook Plus – How Rust Works (WS8.6)
Optional: 8.11 Rusting & Salt Water page 262
page 262 Q’s 1 - 4
page 262 Q’s 5 - 8
page 262 Q 10
Check out: Youtube Combustion http://www.youtube.com/watch?v=gKtaCFs3xcI
page 264 Q’s 1 – 7
page 264 Q’s 8 – 9, 12
page 268 Q’s 1 – 12
page 268 Q’s 13 - 21
* RECYCLING – page 272 do Question 13
Class notes
type of physical properties
maleabilityductility
elasticity
opacity - transparent, opaque, translucent, reflective
colour
shiny or dull
size
shape
texture
hard or soft
squishy
solid liquid or gas
Candle observations
1.Rates of reaction
Expt 8.7Aim: To observe the effect of temperature on a reaction
Method
1. observe the reaction between HCl and Marble chip . Record your observation in the results table
2.gently heat the testtube containing acid and marble chip. observe and record results
Results
Observation table
on a scale of 1 to 5 this reaction was a
on scale of 1 to 5 this reaction was a
Complete the questions
1. what indicated that a reaction was occurring?
2. how did this indication change when you heated the solution?
3. how does heat affect the rate of the reaction
Conclusion:
Effect of temperature.
Increasing the temperature increases the rate of reaction because the particles involved in the reaction are moving faster and bump into each other more often. This speeds up the reaction
Effect of concentration
Increasing the concentration increases the amount of particles in the slution available to take part in the reaction . so the reaction rate increases
Effect of surface area
By increasing the surface area - having a powder instead of a lump this increases the amount of places the reaction can take place. This increases the reaction rate.
complete question 1 to 9 p273
Rusting
Rusting is a form of combustion. This is where oxygen and water combine with iron. This is a slow reaction that may take 100 years to complete.Rust Investigation 8.9
Set up the equipment and draw a clear well labelled diagram to describe the apparatus used in this investigation.
Diagram
See board
Results
After 4 days the rusting looked like this
Diagram
After 6 days (wednesday lesson) the rusting looked like this and the water level was here.
(leave some space to do this diagram)
Conclusion
(leave 4 lines for some writing and a chemical equation)
Oxygen gas in the air inside the beaker has been converted to rust and has moved out of the air in the beaker. This means the water level inside the beaker has risen ( because oxygen has been taken out).
Combustion Reactions
Combustion reactions Are reactions where things are burnt in oxygen. We give them a special name - oxidation reactions. When an element combines with oxygen we say it has been oxidised. This can happen quickly or slowly.An example of a slow oxidation reaction is rusting - here oxygen combines with iron to form iron oxide.
An example of a fast oxidation reaction is burning gas to heat water on the stove. Here we are burning propane to form carbon dioxide and water.
A general equation for this reaction is
(fossil fuel containing carbon) Fuel + oxygen ---> carbon dioxide and water
- What is a fossil fuel? List three examples of fossil fuels- Remains of past living organism - eg coal , gas , oil
- List and describe three examples of useful oxidation reactions. - fuel, , heating, decomposition of food,
- Write a word equation for each of the three examples listed in question petrol + oxygen ----> water + carbon dioxide + heat
Fruit + oxygen -----> water and Carbon dioxidewood + oxygen ----> water + carbon dioxide
Questions 1 to 8 p 276
A new breed of materials
Plastics are synthetic ie they are manufactured and do not occur naturally. Plastics have only been around for 100 years. They are the product of combining C, H, O as molecules in a repeating patternFibres
Natural fibres are found in nature. Egs. linen from flax plants, cotton, wool, silk from silk worms. We often spin these fibres to produce a regular thickness as a thread that can then be woven.
Synthetic fibres are useful because they long lasting, easy care, light, hold their colour. Egs include polyester, nylon, spandex. These fabrics are made by heating the plastic and pushing it through a spinneret to make a thread. it is then woven to make the fabric.
Blended fabrics are made of a combination of natural fibres and synthetic fibres to make a fabric with the properties we want. an eg is spandex combined with cotton and polyester to make leggings/skins.
Soaps and detergents
these are chemical that are used for cleaning - they dissolve grease
They have the physical properties of feeling slippery, solids or liquids , can be colourful
They have the chemical properties of ; dissolve grease, biodegradable,
Physical properties - we use our senses to detect these (hard, soft, smell, colour, slippery etc)
Chemical properties - the thing the chemical can do- the way it reacts with other chemicals- ( acids are sour and corrosive) (Metals react with acids to produce hydrogen gas)
PLastics as packaging
Designing an experiment to investigate corrosion in different metals and under different conditions
1. the variables are - air, water, salt water, acid,2. the control is oil
If a metal corrodes I would expect to see_colour change, going dull no longer shiny _
I would see a difference if I compared this metal to a piece of the same metal that is not exposed to the variable ; air, water, sea water, ___
Draw a diagram of the set up - label all the parts
How will you record your observations?
Design an experiment to identify which substance gives out the most heat when it is burnt.
the variables are:
the things we will make sure are the same between all the substances we test are
are
the control is
The equipment will be set up like this (diagram 5 lines high)
To measure the heat given off we will .....measure the increase in temperature of 5 mLs of water
Results Table
hmwk ques 1 and 2 p 278
3 / 0.3 = 10 C/g
Find three more fuels that you predict are the best fuels -that is highest temperature per gram
What do they use as fuel in africa or qatar